Sample code for 30+ languages & platforms
JavaScript

HTTP Request Boundary Property

Explains and demonstrates the HTTP request Boundary property. For multipart HTTP requests, Chilkat auto-generates a boundary string when the Boundary property is left unset (or empty). For example:
POST /something HTTP/1.1
Content-Type: multipart/form-data; boundary=------------090207000006060206010508
Host: domain
Content-Length: 378

--------------090207000006060206010508
Content-Disposition: form-data; name="fileA"; filename="fileA.txt"
Content-Type: text/plain

This is the contents of file A
--------------090207000006060206010508
Content-Disposition: form-data; name="fileB"; filename="fileB.txt"
Content-Type: text/plain

This is the contents of file B
--------------090207000006060206010508--

If the Boundary property is set, then Chilkat uses it. For example, if the Boundary property is set to "ABC123HELLOWORLD"
POST /something HTTP/1.1
Content-Type: multipart/form-data; boundary=ABC123HELLOWORLD
Host: domain
Content-Length: 318

--ABC123HELLOWORLD
Content-Disposition: form-data; name="fileA"; filename="fileA.txt"
Content-Type: text/plain

This is the contents of file A
--ABC123HELLOWORLD
Content-Disposition: form-data; name="fileB"; filename="fileB.txt"
Content-Type: text/plain

This is the contents of file B
--ABC123HELLOWORLD--
Note
This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.
JavaScript
var req = new CkHttpRequest();

req.HttpVerb = "POST";
req.Path = "/something";
req.ContentType = "multipart/form-data";

req.AddStringForUpload("fileA","fileA.txt","This is the contents of file A","utf-8");
req.AddStringForUpload("fileB","fileB.txt","This is the contents of file B","utf-8");

// When the Boundary property is empty (has not yet been set)
// Chilkat auto-generates a random boundary for the request.
// This should almost always be sufficient.
// For example, one can see the generated boundary here:
console.log(req.GenerateRequestText());

// If the Boundary property is set to a specific string, then the
// request will use it:
req.Boundary = "ABC123HELLOWORLD";
console.log(req.GenerateRequestText());